Overdrive—Water x4 (When you summon this creature, you may tap another 4 Water cards in your mana zone. If you do, get the following Overdrive ability.)

Overdrive When you put this creature into the battle zone, reveal the top card of your opponent's deck. If it's a spell, you may cast it for no cost, and put it into its owner's graveyard. If it's not a spell, put it on the bottom of your opponent's deck.